The present invention relates to a device for use with drain openings in cascading water tanks of a battery formation apparatus, and in particular, the present invention relates to a device which can be used as both a drain extension and an overflow outlet in these water tanks.
One of the classic problems in the battery industry is controlling temperature and time of battery formation. When electrolyte is first added to an unfilled, unformed battery and interacts with the paste on the plates of the element assembly within the battery, a great deal of heat is generated; this heat is referred to as the heat of neutralization. Heat further continues to be generated by the battery during the formation and charging process while high current flow is passed through the batteries. It is unecomonical to purchase and maintain sufficient equipment to form batteries at a current low enough to prevent the batteries from heating.
Various apparatuses have been devised to cool batteries during the neutralization, formation, and charging process in order to avoid internal overheating of the batteries which, if not properly controlled, will result in destruction of the battery. The old problem of dissipating heat which is generated during the formation of a battery is now further aggravated by the widespread use of plastic battery cases throughout the automotive battery industry. Unlike the rubber, composition, or glass cases previously used, plastic cases generally tend to have a low heat transfer coefficient which tends to insulate the interior of the battery, retain generated heat thereinside, and make it particularly susceptible to overheating.
Several approaches have been suggested to overcome this problem of maintaining proper battery temperature during formation. One approach which has been used is to spray the batteries with water or other cooling fluid. This approach, however, is not especially successful since the water spray does not have a sufficiently efficient heat conducting capacity. Chilled electrolyte has also been used as an approach for reducing the heat of neutralization, but this is an expensive technique, and while it reduces the high initial peak, the possibility of high heat developing during formation exists as well as the possibility of having a delayed thermal runaway.
One of the more successful solutions to the problem of heat generation in batteries during formation has been the development of the water bath technique in which the batteries are contained in tanks wherein cooling water is circulated during the battery neutralization, formation, and charging process. In general, a method and apparatus have been developed to form a maximum amount of floor space and still maintain appropriate temperatures by providing stackable, water-filled tubs for holding the batteries during formation. In one mode of operating the stacked tubs, water is continuously fed into the uppermost tub and from there allowed to overflow or cascade to the next lower tub and so on. Another approach to providing the tubs with water is to fit each tub with a drain through which the water in the tub may be eliminated while cooling water is continuously added to the tub. The drain may lead to the next lower tub in the stack of tubs so that the cooling water will pass downward through the tubs or it may simply lead away from the tubs entirely.
At least two significant problems arise when the drain structure is provided to allow the water to pass to the next lower tub. Oftentimes the drains are simply openings which project only slightly beneath the bottom of the upper tub, and the water must fall uncontained through the space between the bottom of the upper tub and the surface of the water in the lower tub. Consequently, the falling water splashes as it hits the water in the tub, and this can lead to undesireable splashing onto the terminals of the batteries which are being formed. Furthermore, when these drains are provided in the tubs, there is often no consideration given to preventing the water level from raising too high around the batteries being formed or to simply preventing the water from reaching a stage where it overflows from the tub.